So... despite the issues... it was good to be back! And God Bless Cindy....
She knew Fleck isn't feeling up to par but we got some nice work. She helped me to ride him therapeutically. Instead of trotting on the icky diagonal, she had me swap diagonals every 3 strides to help keep him and me from bracing. She had me focus on lifting my seat bones instead of sending them (and thus his shoulders) down. Even at the canter, I need to almost alternate lifting my seat bones. I'm not sure that's exactly what she wanted but it was what I was doing and she was saying yes.
Then we isolated it. He doesn't want to bring his right hind laterally. I know this... Cindy saw it. Even leg yielding and tracking and standing, he wants to hold it medially. (almost like a dog with a dislocated hip). When I tried to get him to turn on the haunches to the right (which is always his tough side) he spun. When I sat to the right, instead of letting him fling me to the left, he panicked! BUT.... he did do it after a tantrum and realized he could.
So I'm still thinking right hip or some abductor muscle injury.
But it was good to be back. And he was going quite nice when he could. :) We got a bit more sit and lift than usual. :)